118 
LECTURE IX. 
nute animals on whi^i Spiders prey. The legs 
are eight in number, and at the end of the body 
are four or .five small teats or organs through 
which the animal draws its thread. Each of these 
teats is pierced with a vast number of holes through 
each of which proceeds a distinct thread, and the 
animal can either draw its thread from all the 
holes at once or by any particular number ^ in 
short M^hat we call a single spider’s thread may 
consist, according to some computists, of not less 
than six thousand distinct filaments. The size to 
which the European spiders arrive is not very 
great, but the hotter regions of Africa and Ame- 
rica produce spiders of a size so gigantic as to be 
fonnidable even to birds and many other animals 
on which they prey. One of the chief of these is 
the Aranea Avicularia or Bird-catching Spider, of 
which very capital specimens may be seen in the 
Leverian Museum. These Spiders are found 
principally in the hotter parts of South- America. 
The genus called Acarus or Mite contains the 
smallest of all known Insects, as w^ell as some of 
considerable size. The mites are a very uumerous 
race. The generic character consists in having 
eight legs, and in many species a kind of claspers. 
